Process of producing lustrous threads, &amp;c., from viscose.



I To a whom itmdy concern.-

ject of the King of Prussia, German cose solution.

many,

MAX MUL R. or ALTDAMM. GERMANY.

PROCESS OF PRODUCING LUSTFOUS THREADS,

Specification of Letters Patent.

Anplication filed April 24, 1906- Serial No. 318,511.

a sub- Emresiding in Altdamm, Prussia, Gerhave invented certain new and useful Improvements in Processes of Producing Lustrous Threads, Bands, Strips, &c., from Viscose, of which the following 1s a specification.

My invention ducing lustrous Be it known that 1, Max Mi'ILLEn,

peror,

threads and the like from vis- It is known that lustrous threads or the I like can be produced from viscoseim ex- 0 when. microscopically have 'a smooth'structure provided with some. longitudinal strips,

/-with fine scales.

sulfuric'. acid acts on the vis-.

Here I loss in material.

- same time ample, as described in the German Patent o. 7 0,999-if it is permitted to pass out of suitably-formed openings into a solution of sulfate of ammonia or into acids.

When using sulfuric acid for the purpose indicated, it is shown that diluted acid acts but slowly, and the water present gives .a slimy constitution to the thread or film, which on working farther up causes eat If the action of difiited. acid is supported by heat, the thread does indeed become firmer and is more easily worked; but as thegaseous' products of decom amp e, hydrosulfuric' acid, carbonic acid-are almost insoluble, or at all events soluble with d1fficulty,m warm liquid, they esca e as and occasionally pass as smal bubbles through the sides of the tube of cellulose hydr-ate, which represents the first stage of thread formation. A ments, in which sulfuric acid of varying concentration .(containing between five per cent.

and forty per cent. of sulfuric acid) was em-. ployed, show that all the: threads produced examined no longer but show a slight similarity to a thread which is thickly covered Concentrated cose solution 1n quite s1m1'lar 'manner. the gaseous products escape/for wantof a'solvent, and the formation of a furic acid is dilute so far as the disturbing development of'gas is avoided, and if at the theso'r'tenin ing-Water on the threa in process ofiformation is counterbalanced by adding a suitable quantity 'ot salt', a product of. conspicuous- I qualitiesin regard to strength, luster, and

relates to the method of proosltion of the viscose solution-for ex-' ases,

long series of ex'peri lustrous thread; -or the like is entirelg thwarted; .but if the sul-T' action of the dilutthose of the heavv metals, are suitincludin d naturally also all those salts and able, an

once further decomposed, with separation of .cellulose hyldrate. As the viscose solutions ossess a 'gh percentage of free soda, it is inevitable that almost the entire ammonia escapes in the form of gas, espe. cially as the precipitation solutions must 'be employed at a higher temperature. That process, because of the high commercial value of ammoniafis there more expensive through the losses or through the cost y apparatus for regaining the same. Other sulfates are not suited for the present purpose, for some-as, for instance, sulfate of zinc'or sulfate of magnesia when .in viscose solutionthrou h reciprocal decomposition yield insolub e salts of cellulose thiocarbonic acid, from which cellulose hy-' drate can be separated only through further suitable action. The others, such assulfate viscoses which are insoluble in salt solutions and salt solution by chemical agencies or heat'can bring about the formation of cellulose hydrate. For instance, one does not succeed with the most concentrated sulfate of soda inproducin lustrous threads from viscose solutions. n thev otherhand, the precipitating-bath just described, com osed .of solution of bisulfate of sodium and s A furic acid, is well suited for the urpose, even at room temperature. The s lght commercial value of the materials employed and the fact that'bisulfate sulfuric acid and caustic soda are easily useful in the form of sulfate of sodacalculated to assure for the bisulfate process precedence as. compared with the 1 employment of sulfate of ammonia.

Patented Nov. 20, 1906.

oxids or elements which when incontact with hydrate from viscose lose xanthogenate of ammonia, which is at 800-, FROM VISCOSE;

elasticity is obtained. All soluble sulfates,"-

dissolved sixty kiloore essentially and only the further treatment of the viscose In order to obtain .the very shiny product decomposition of the viscose aimed at by the process in the form of threads, bands, &c.,

' the sufliciently purified and concentrated viscose solution is permitted to pass out of suitably-formed openings into a solution of the composition described, and the separated cellulose hydrate is collected by winding it onto spools or reels or in any other manner in order to bring it into convenient form to be further workedup.

What I claim as m invention, and desire to secure by Letters atent, is-

1. The method of producing threads of the character described consisting of permitting the viscose solution to pass out through suitably-formed openings into a precipitatingbath containing sulfuric acid and a salt.

2. The method of producing threads of the character described consisting of ermitting the viscose solution to pass'out o suitablyformed openings into a precipitating-bath containing sulfuric acid and a soluble sulfate salt.

3. The method of producing threads of the character described consisting of permitting 

